Patent GB-796685-A (GB)
Title: Improvements in or relating to printing mechanisms
Inventor: WOODHEAD JAMES
IPC: B41J2/275
Filed: 1954-08-31
Abstract: 796,685. Selective printing. BRITISH TABULATING MACHINE CO., Ltd. Aug. 31, 1954, No. 25255/54. Class 100(4) [Also in Group XL(b)] In a record card controlled wire printing apparatus the electronic translating mechanism for the sensed column is simplified by controlling the circuits by commutators rotating in synchronism with the card feed. The cards are fed as described fully in Specification 695,083 [Group XIX] from a hopper 1 by impelling rollers 2 through a slot 35 until positioned and engaged by grippers 5 of a band 4 driven step-by-step by a driving drum 31. The cards thus pass holes 8 in the base plate behind which photo-electric cells are positioned and above which are lamps. A wire printer head 9 four column spaces from the holes 8 has thirty-five electro magnets 39, Figs. 1 and 3, arranged in a circle each of which controls a wire 44 attached at one end to an arm 43 of the electromagnet and passing through a tube 45 and guides 48-51 so that the ends of the wires are arranged in a rectangle seven wires by five in the last guide 51. When advanced by the magnets the wires produce an impression on the cards through an ink ribbon 37. The main driving shaft 19 which drives the card feed mechanism also through gears 55, 56 drive in synchronism a shaft 54 which carries four commutator drums 11-14. Each drum is divided into three segments so that it is arranged to rotate once for every three columns of the card feed. Each segment has insets fed from a single slip ring and brushes 103-106 and is contacted by sets of brushes 15-18 in such a way that the component wires of the character to be printed will be advanced corresponding to the hole of the card being sensed at that moment in conjunction with a zoned position if previously sensed in that column. Each card has three zone index positions O, X, Y, which are sensed first simultaneously and digit position 1-9 sensed sequentially afterwards. Each zone position has two corresponding valves the first of which is fired if the zone position is sensed and acts as a temporary storage, the second a gate valve is subsequently fired when a digit postion is sensed this combination together with a connection of the commutators energizing magnets to produce the appropriate letter for that column of the card. Separate storage and gate valves cause a digit to be produced if no zone position has been sensed while zone position X, Y, alone can be used to represent the values 10 and 11 for recording pence. A cam on a shaft 34 closes contacts while the fourth and eighth columns are being sensed thus preventing printing before the card reaches the printing head and while all the photo-electric cells are illuminated during the gap between cards. Contacts are also opened to prevent printing by card lever 131 when no card is present. If a hole in the X or Y position is used for designation for example to indicate a decimal point its effect is suppressed to allow the digit to be printed from the same column. Similarly means are provided to render the digit photo-electric cells ineffective if desired or to suppress the information of a complete column. Specifications 684,273 and 691,668 [Group XIX] also are referred to.